Deterministic rendering of active content

ABSTRACT

Active content is deterministically rendered in a stable format that is independent of any particular targeted environment, which the active content may subsequently be rendered to. Environmental and dynamic dependencies are removed from a specification associated with the active content for purposes of producing a stable and consistent specification for the active content. The stable and static specification is used to subsequently render the active content into the stable format for any targeted or desired environment.

FIELD

This application relates to data processing and in particular totechniques for the deterministically rendering of active content.

BACKGROUND

Increasingly documents are being natively created and subsequentlystored in an electronic environment. Reliance on paper-based media is onthe decline. In the past, important documents (e.g., legal, work relateddocuments, etc.) were almost exclusively produced on paper andsubsequently stored in filing cabinets, court libraries, safety depositboxes, etc. This is no longer exclusively the case as more and moreelectronic documents are being admitted into court proceedings asevidence and being relied upon by individuals and enterprises as masterversions of their contracts, wills, deeds, papers of incorporation,titles, and other important documents.

One problem associated with relying on electronic versions of documentsis that often documents may be stored in electronic formats that arereadily and easily modified. This is particularly relevant in workflowsituations where a document may have counter signatures for approvalthat is applied to it. Documents may be modifiable in or produced withelectronic editors, which permit the contents of the documents to bechanged. Furthermore, even some bitmap versions of documents aremodifiable within an image editor even though bitmap formats are notgenerally thought of as capable of being modified. Thus, if a finalizeddocument is capable of being subsequently modified, then there mayalways exist a question, with any given version of that document, as towhether it is the true finalized version or as to whether it has beensubsequently tampered with.

Another issue with relying on electronic versions of documents is thatoften the native format of the data that comprises the electronicdocument is associated with inherent variability. That is, manydocuments are no longer static in nature, such that some aspects of adocument are dynamically resolved based on the environment in which theyare rendered and/or based on execution of some program logic that may beembedded within the document and executed with the document when it isrendered to a target environment.

So, the same document rendered on different displays, devices, orenvironments may actually produce different versions of content and/ordifferent visual appearances. For documents signatures, such a situationcan be particularly problematic because parties associated with thedocuments may each assert that they have the proper version or masterversion; but, each version is in fact different from the other versionseither in terms of visual appearance and/or in terms of actual content.

Therefore, although reliance on paper-based media is waning there isstill some reluctance and some remaining technical issues associatedwith completely removing paper dependency from commercial and legalprocesses.

SUMMARY

According to an embodiment, a method for rendering active content withina document into a stable and environmentally independent format isprovided. A document containing an active piece of content is acquiredfor rendering. Presentation attributes for the content are ensured to berecognizable. Portions of the content that are environmentally dependentare ignored and remaining portions of the content are rendered in anon-modifiable, stable, and/or consistent format.

Other features will be apparent from the accompanying drawings and fromthe detailed description that follows.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments are illustrated by way of example and not limitation in thefigures of the accompanying drawings, in which like references indicatesimilar elements and in which:

FIG. 1 is a diagram of a method for rendering active content in a nonmodifiable format, according to an example embodiment of the invention.

FIG. 2 is a diagram of a method for presenting active content in anenvironmentally independent format, according to an example embodimentof the invention.

FIG. 3 is a diagram of a method for rendering active content in anenvironmentally independent format, according to an embodiment of theinvention.

FIG. 4 is a diagram of a deterministic content rendering system,according to an example embodiment of the invention.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of an embodiment of the present invention. It will beevident, however, to one skilled in the art that the present inventionmay be practiced without these specific details.

As used herein, the term “content” refers to electronic data that isconsumed by viewers on displays, devices, automated services,print-based media, or page/display-based media. So, content may refer todata associated with readable text, data associated with graphics, dataassociated with images, data associated with video, programmaticcontent, scripts, or data associated with various combinations of eachor all of these. Some media may be page/display or view-based, such asWorld-Wide Web (WWW) formatted or paged media embodied in browsers andaccessible over the Internet or modified via editors. Content that islogically related to form a topic, a website, a presentation, or apublication may be referred to as a “document.” A “piece of content”refers to all or some subset of defined content. So, content of adocument may have a specific header or footer or event section that maybe designated as a “piece of content.”

The electronic data associated with the content may be represented in avariety of programming or data mark-up languages, such as, but notlimited to, Adobe® Portable Document Format (PDF), Hypertext Mark-upLanguage (HTML), Extensible Mark-up Language (XML), Extensible StyleSheets Language (XSL), Word®, WordPerfect®, JAVA®, ActiveX®, Tag ImageFile Format TIFF, etc.

“Active Content” refers to a special type of content that is representedby electronic data, which includes at least some data that is dynamic orvariable. By variable it is meant that a presentation format for theactive content may vary based on an environment or media to which thedata is rendered. Variable data may also refer to substantive content(as opposed to presentation content) that is executed dynamically whenthe active content is rendered to a target environment or media. Activecontent that is executed when rendered may also be referred to as“active content.” Some examples of active content may include, by way ofexample only, programmatic code, multimedia content, guides drawn on apaged media, embedded JAVA, embedded ActiveX, embedded forms, contentspecifications that permit fonts or other presentation attributes (e.g.,text effects, underlining, bolding, font sizes, font colors, fontstyles, etc.) to be dynamically resolved based on a context of anenvironment that the active content is being rendered to, and the like.Moreover, since a document may be viewed as a type of content, somedocuments may also be properly considered “active documents.”

A target “environment” refers to a processing context within which agiven piece of content is rendered. So, a target environment may use aspecific version of a service and/or a specific version of an operatingsystem (OS) on a specific device or media (e.g., paper, display, browserpage, etc.). One environment is considered to be different from anotherenvironment when it uses a different version of a same service, adifferent service altogether, a different version of a same OS, adifferent OS altogether, or a different device or media. Furthermore,some environmental factors may be outside the content being renderedentirely or external to the content, such as a specific data and time,the identity of a user, information supplied from the user via an activeform, information acquired from a storage device, information obtainedfrom a network, and the like. So, the target environment may be broadlystated as a context associated with rendering the content that can bespecific to the target environment and to the content that is outside orexternal to the content entirely.

With this context, the description of various deterministic contentrendering services and systems are now described.

FIG. 1 is a diagram of a method 100 for rendering active content in anon-modifiable format, according to an example embodiment of theinvention. The method 100 (hereinafter “rendering service”) isimplemented in a machine-accessible and readable medium and isoperational over a network. The network may be wired, wireless, or acombination of wired and wireless.

The rendering service may be implemented within or callable from anexisting content viewer or editor. For example, a new feature may beadded to the Adobe® Acrobat® product that permits the rendering serviceto be called. It is to be understood, however, that the renderingservice may be a stand alone server-based or client-based service thatis activated from within another service or system or that is manuallyactivated. It may also be network independent or network-enabled.

The rendering service is designed to produce a deterministic andnon-modifiable format specification for a piece of active content. Forexample, a PDF signed document may be viewed as a piece of activecontent for which the rendering service processes against to produce anon-modifiable and stable version of that signed document, such that thestable version is capable of being rendering on a variety of disparateenvironments and on a variety of disparate devices and it still visuallyappears the same and includes the same content across environments,across devices, and/or across media. By non-modifiable it is meant thatthe stable version is not altered or not altered in a manner that wouldbe different from the stable version. So, technically a modificationthat does not alter the stable version in any manner may occur. Thestable version reproduces a consistent version of the content acrossenvironments, devices, and platforms.

The technique for achieving this will now be discussed within theprocessing context of the rendering service with reference to FIG. 1.Accordingly, at 110, the rendering service acquires an active piece ofcontent for rendering. Acquisition may occur in a variety of manners.For example, an existing document that represents the piece of activecontent may be loaded within a content viewer or content editor when therendering service is activated, such that the rendering service canidentify the name of the piece of content or acquire the data frommemory and/or storage associated with the piece of active content. Inother cases, the rendering service may actively acquire the piece ofactive content from storage when instructed to do so using an identifierassociated with the piece of active content, such as a file name, etc.

At 120, the rendering service ensures that presentation attributesassociated with the active content are recognized by the renderingservice. That is, fonts, effects, and other presentation details mayinclude tagging schemes or other descriptions within a specificationassociated with the active content, and the rendering service determinesif those tags or descriptions are acceptable or known to the renderingservice. Known presentation attributes may be resolved by the renderingservice by checking policies, tables, specifications, or other datastructures that define acceptable and known presentation attributes forthe rendering service. A presentation attribute is considered acceptableif it can be deterministically rendered across a plurality of disparateenvironments and/or devices.

According to an embodiment, at 121, the rendering service may alsodetect that some attributes are known and acceptable; and yet theseattributes may still not be universal in their application and usageacross some environments or across some devices. For example, some fontsmay be deterministically rendered and known across some environments anddevices but not across all environments and devices. So, a particularfont may appear differently on one device from another device, such asone display screen from another display screen. In such situations, therendering service may elect to not continue with processing the activecontent at all or may elect to select a default universal font and issuea warning notification.

At 122, the rendering service determines sub-content included within theactive piece of content, which can be deterministically renderedindependent of any particular target environment or device. If therendering service is unsure how some sub-content or presentationattributes associated with the sub-content will be handled within theactive piece of content, then the rendering service will exclude thesub-content in question from the rendering. That is, a deterministicrendering is processing that the rendering service is confident will bethe same across multiple environments and devices irrespective ofprocessing contexts.

At 130, the rendering service ignores portions of the active contentthat are environmentally dependent; or, stated another way, that aredependent upon a particular processing context when the active contentis rendered to a target environment, device, or media. In some cases,some identified environmentally dependent portions of the sub-contentmay be, at 131, automatically converted or transformed intoenvironmentally independent attributes by selecting default attributes.So, if a specification for the active piece of content defines somepresentation attributes associated with some portions of the sub-contentas being selectable depending upon a variety of contexts orenvironments, then the rendering service may map those availableselections to environmentally or context neutral/independent selections.Additionally, at 132, the rendering service actively excludes portionsof the active content identified as having active sub-content embeddedtherein. So, any executable logic included within the active piece ofcontent, which is inherently non deterministic and potentiallyenvironmentally dependent, is proactively excluded by the renderingservice.

At 140, the remaining portions of the active piece of content that werenot actively excluded and any replaced portions (portions that may havebeen replaced with environmentally and context independent attributes)are rendered to a non-modifiable and stable format for the active pieceof content. This version of the active piece of content is consistentand may be relied upon to be deterministically rendered to produce thesame content and produce the same visual experience across multipledisparate environments, multiple disparate devices, and multipledisparate media.

In an embodiment, at 150, the rendering service may then present thenon-modifiable and stable format of the active piece of content on atarget display for consumption by a viewer or requestor. In anothercase, at 160, the rendering service may send the non-modifiable andstable format of the active piece of content to a printing device orprinting system for subsequent output to print media. It is noted thatthe viewing form of the stable content may be the same as the printedform of the stable content. That is, the rendering of the active pieceof content from its stable form can be consistent across environments,across devices, and across media (display/paged media versus paper-basedmedia).

FIG. 2 is a diagram of a method 200 for presenting active content in anenvironmentally independent format, according to an example embodimentof the invention. The method 200 (hereinafter “presenting service”) isimplemented in a machine-accessible and readable medium and isaccessible over a network. The network may be wired, wireless, or acombination of wired and wireless. The presenting service presents anenhanced or alternative view of the processing associated with therendering service represented by the method 100 of the FIG. 1.

At 210, the presenting service receives a request to view a stable formof an active document. In some cases, this request may be received fromwithin a content viewer or content editor, where the active document isloaded or where an identifier for the active document is supplied suchthat the presenting service may acquire the data associated with theactive document.

At 220, the presenting service generates a stable form of the activedocument by rendering or converting data associated with the activedocument into a format (stable form) that is independent of variablecontent or variable presentation details defined in the active document.So, at 221, the presenting service parses the data associated with theactive document or parses a specification associated with the activedocument for purposes of producing a deterministic formattedspecification for the stable form. The specification defines therendering of the stable form.

The specification may be in any language format, such as but not limitedto, an extensible mark-up language schema definition (XSD), data typedefinition (DTD), database schema, etc. In performing this processing,the presenting service will exclude portions of the active document thatare associated with active sub-content (executable logic embedded in thedata associated with the active document). At 223, the presentingservice may also modify or actively exclude environmentally dependentattributes or content associated with variable content or variablepresentation of content. Again, lists, specifications, tables, policies,or other data structures may be used and evaluated by the presentingservice for purposes of determining what is to be excluded and whatmight be modified for purposes of retaining just environmentallyindependent content and attributes within the active document in itsstable form.

According to an embodiment, at 224, the presenting service may alsoproduce a log associated with converting an original specificationassociated with the original active document to a stable specificationassociated with a stable form and version of the active document. Thislog may be used as an audit trail or for purposes of report generationor notification. It may list each action taken by the presenting serviceduring the conversion and actively identify excluded content, modifiedattributes, etc.

At 230, the presenting service presents the stable form of the activedocument within a context of a content viewer. That is, the activecontent is rendered and presented within a display in its stable form.The viewer of this stable form is assured that what is present in thisstable form will remain there across platforms, environments, and mediarenderings. In this manner, the viewer can rely on this version of theactive document as being consistent and stable. This helps facilitatereliability for documents that are dependent upon a stable and nonmodified version, such as documents that include a signature. So, asigner can be assured that a version of a document he/she signs is notgoing to change and when it resurfaces it will match with what thesigner has recorded and has previously noted.

The stable form may also be managed by the presenting service, such thatthe stable version is not modifiable and is consistently retrievablewith subsequent iterations of the document on demand.

FIG. 3 is a diagram of a method 300 for rendering active content in anenvironmentally independent format, according to an embodiment of theinvention. The method 300 is implemented as instructions within amachine-accessible and readable medium and is operational and accessibleover a network. The network may be wired, wireless, or a combination ofwired and wireless. The instructions may implement, among other things,the methods 100 and 200 of the FIGS. 1 and 2 and provide for otherbeneficial features described herein and below.

The instructions may be stored on removable media and the removablemedia may be interfaced to a machine where the instructions are uploadedand processed to perform the processing depicted in FIG. 3.Alternatively, the instructions may be prefabricated within memoryand/or storage of a machine and executed. In still other cases, theinstructions may be downloaded from one network machine to anothernetwork machine and processed. In still more cases, the instructions maybe executed remotely on one network machine at the direction of anothernetwork machine or its services.

At 310, the instructions evaluate a first specification associated withactive content. That is, active content is in some electronic format orlanguage and a definition of that content is defined in metadata, suchas a specification (e.g., XSD, schema, DTD, etc.). The instructions maythen use a parser or other techniques to evaluate the firstspecification for the active content being processed for purposes ofrecognizing attributes and data types, which the instructions knows canbe rendered deterministically independent of any particular environmentor device.

At 320, the instructions determine, in response to the evaluation,whether the first specification is convertible to a second deterministicspecification. A deterministic specification is one in which a versionof the active content can be rendered independent of a device, media, orenvironment in which it may be subsequently rendered. That is, adeterministic specification can be used to render the active content ina same visual and substantive format across platforms, environments,media, and devices. A rendered version of the active content producedfrom the deterministic specification is the same regardless of itsrendered environment or context.

According to an embodiment, at 321, the instructions may also issuewarnings when attributes or content are determined to be variable fromthe first specification. These warnings may be screen messages or may berecorded to a log for subsequent consumption and usage. In some cases,at 322, the instructions may select static and stable replacements forsome attributes determined to be potentially problematic in the firstspecification and record these replacements in the second and stablespecification. The replacements are deterministic in nature, which meansthey will produce a rendering from the second specification in aconsistent manner independent of any particular target environment,target media, or target device.

Also, at 323, the instructions proactively exclude active orenvironmentally dependent content from the second specification. Thisagain, permits the second specification to be defined in terms ofdeterministic definitions and processing, which is consistentlyreproducible.

At 330, the instructions render the active content to a stable formatusing the second specification, if the second specification was in factproducible or convertible from the first specification associated withthe active content. If the first specification was not convertible thenthe instructions will stop processing and send notifications that theactive content is incapable of being deterministically rendered.

In an embodiment, at 340, the instructions may present the stable formatin a content viewer for consumption by a viewer. Additionally, theinstructions, at 350, may present the stable format in a first contentviewer and simultaneously present the stable format in a second contentviewer. The two content viewers may be associated with differentversions of the same editor, different editors altogether, differentenvironments, and/or different devices or processing contexts associatedwith the two content viewers. So, the second specification may berepeatedly used to produce a stable and consistent substantive andviewing version of the active content, which is independent of anyparticular environment, device, or media.

FIG. 4 is a diagram of a deterministic content rendering system 400,according to an example embodiment of the invention. The deterministiccontent rendering system 400 is implemented in a machine-accessible andreadable medium and is accessible or operational over a network. Thenetwork may be wired, wireless, or a combination of wired and wireless.According to an embodiment, the deterministic content rendering system400 implements, among other things, the methods 100, 200, and 300depicted and described within the contexts of FIGS. 1-3.

The deterministic content rendering system 400 includes a convertingservice 401 and a rendering service 402. In some embodiments, theconverting service 401 and the rendering service 402 may be integratedwith or callable from a modified content viewer/editor 410. Each ofthese will now be discussed in turn.

The converting service 401 is implemented as software instructions thatevaluate active content or active documents and/or their specificationsfor purposes of determining if the data is capable of beingdeterministically rendered independent of any particular environment,media, or device. The converting service 401 retains the content andattributes that are deterministic from the original data associated withthe active content and either discards the non-deterministic data or, ifpermissible, replaces some attributes associated with non-deterministicdata, with deterministic replacements.

In an embodiment, the converting service 401 is adapted to selectuniversal presentation attributes for inclusion in a specificationassociated with a deterministic version of active content when someexisting attributes detected in a first specification associated withthe active content are resolved to be variable or non deterministic andwhere such replacement is permissible.

According to an embodiment, the converting service 401 is also adaptedto raise warnings when a number of the presentation attributes detectedin a first specification associated with the active content areidentified as being non universal or non standard. Such detection canoccur via preconfigured policy evaluations, other global specifications,other metadata, table lookups, etc.

In still another embodiment, the converting service 401 is adapted toindependently maintain a second specification for the active contentindependent of the first specification. The first specification is anoriginal specification for a non-deterministic version of the activecontent and the second specification is a deterministic version of theactive content. The second specification may be locked down and carriedwith the document as metadata, such that any particular point in time astable form of the active content may be rendered to a targetenvironment, target media, or target device.

The converting service 401 may also log actions that it takes when itconverts a first specification of the active document to a secondspecification. This may be used for auditing, reporting, or notifyinginterested parties or other automated services.

The rendering service 402 receives the second specification from theconverting service 401 and renders the active content into a stable orstatic form or format that is independent of environment, media, ordevice. The rendering service 401 may also present the rendered activecontent on any desired target device, such as a display.

According to an embodiment, the converting service 401 and the renderingservice 402 are integrated within or processed within a context of acontent viewer/editor 401. So, the converting service 401 and therendering service 402 may be implemented as integrated enhancements toexisting viewers or editors to provide the added functionality ofmaintaining a version of an active document or piece of active contentin a static, stable, non-modifiable, and deterministic format thatconsistently is capable of being rendered to a same substantive andvisual format having the same consistent content. This also permits auser to easily compare two different versions visually or via othercontent comparing tools or services.

In still another embodiment, the rendering service 402 may maintainversions of a document having the active content based on signaturesthat appear in the documents. In this manner, a user may select aparticular signature in a particular version of a document that the useris viewing and the rendering service may produce a stable form andversion of the document as it existing when that particular signaturewas generated or signed for the document. In this manner, users may roleback to stable forms of the document and see how that document appearedwhen a particular signature was used to sign the document.

It is also noted that techniques presented herein and above permitcontext-dependent information associated with content to be ignored in arendering to a target environment or platform or to be convertedconsistently to context-independent information that is consistentlyrendered to the target environment in a same format. In some cases, somevariations may be permissible. For example, content associated withvideo or animation may be viewed from different points in time andcontent associated with three dimensions may be viewed from differentperspectives. However, in these cases each point in time and eachperspective will present the same consistent viewing of the content forthat point in time or that perspective.

The above description is illustrative, and not restrictive. Many otherembodiments will be apparent to those of ordinary skill in the art uponreviewing the above description. The scope of embodiments shouldtherefore be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled.

The Abstract is provided to comply with 37 C.F.R. §1.72(b) and willallow the reader to quickly ascertain the nature and gist of thetechnical disclosure. It is submitted with the understanding that itwill not be used to interpret or limit the scope or meaning of theclaims.

In the foregoing description of the embodiments, various features aregrouped together in a single embodiment for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting that the claimed embodiments have more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Description of the Embodiments, with each claimstanding on its own as a separate exemplary embodiment.

1. A method, comprising: acquiring active content for rendering;ensuring presentation attributes for the content are recognized;ignoring portions of the content that are environmentally dependent; andrendering remaining portions of the content in a stable format.
 2. Themethod of claim 1, wherein ensuring further includes issuing a warningwhen a number of the presentation attributes are recognized but areassociated with attributes determined to not conform to a predefinedfile format specification.
 3. The method of claim 1 further comprising,selecting default attributes for a number of presentation attributeswhen a specification for the content permits.
 4. The method of claim 1,wherein ensuring further includes determining that the content iscapable of being deterministically rendered independent of a specifictarget environment or specific target device.
 5. The method of claim 1,wherein ignoring further includes excluding a number of the portions ofthe content identified as active sub-content that is dynamicallyexecuted when the content is rendered to a target environment.
 6. Themethod of claim 1, wherein rendering further includes presenting thenon-modifiable format of the content on a target display.
 7. The methodof claim 1, wherein rendering further includes sending thenon-modifiable format of the content to a printing device or system foroutput to print media.
 8. A method, comprising: receiving a request toview a stable form of an active document from a content viewer;generating the stable form of the active document by rendering thedocument independent of variable content; and presenting the stable formof the active document within a context of the content viewer, whereinthe context does not allow the stable form to be modified.
 9. The methodof claim 8, wherein generating further includes producing adeterministic format specification for the stable form of the activedocument.
 10. The method of claim 9, wherein producing further includesexcluding portions of the variable content that are associated withactive sub-content and selecting other portions of the variable contentthat provide for dynamically selectable options.
 11. The method of claim8, wherein generating further includes modifying or excludingenvironmentally dependent attributes or content included in the activedocument, wherein the environmentally dependent attributes or contentare associated with portions of variable content included within theactive document.
 12. The method of claim 8, wherein generating furtherincludes producing a log associated with converting an originalspecification of the active document to a stable specificationassociated with the stable form of the active document.
 13. Amachine-accessible medium having instructions included thereon, theinstructions when accessed by a machine perform a method, the methodcomprising: evaluating a first specification associated with activecontent; determining whether the first specification is convertible to asecond specification, wherein the second specification is deterministicand permits the active content to be rendered in a stable formatindependent of a target environment; and rendering the active content tothe stable format using the second specification, when the firstspecification was convertible to the second specification.
 14. Themedium of claim 13 further comprising instructions to issue warningswhen some attributes or when some sub-content defined in the firstspecification is determined to be variable.
 15. The medium of claim 14further comprising instructions to select static replacements for theattributes or sub-content, wherein the static replacements are definedin the second specification.
 16. The medium of claim 13 furthercomprising instructions to exclude active or environmentally dependentcontent defined in the first specification from being represented withinthe second specification.
 17. The medium of claim 13, wherein renderingfurther includes instructions for presenting the stable format in acontent viewer, wherein the stable format is not capable of beingmodified.
 18. The medium of claim 13 further comprising instructionsfor: presenting the stable format within a first content viewer; andpresenting the stable format within a second content viewer; wherein thefirst and second content viewers are at least one of associated withdifferent editors, associated with different versions of a same editor,and associated with different processing environments from one another.19. The medium of claim 13 further comprising instructions to processthe instructions when the instructions are referenced within processingcontext of a content viewer or editor.
 20. A system, comprising: aconverting service; and a rendering service, wherein the convertingservice is to convert a first specification associated with activecontent from an environmentally dependent form to an environmentallyindependent form associated with a second specification, and wherein therendering service is to present the active content in a stable format inresponse to the second specification.
 21. The system of claim 20,wherein the converting service and the rendering service are adapted tobe processed within a processing context of a content viewer or editor.22. The system of claim 20, wherein the converting service is to excludeactive sub-content defined within the first specification fromrepresentation within the second specification.
 23. The system of claim20, wherein the converting service is to select universal presentationattributes for inclusion in the second specification when the firstspecification permits selection of attributes to be dynamically resolvedin response to a target environment, and wherein the universalpresentation attributes are static and available across multipleenvironments include the target environment.
 24. The system of claim 20,wherein the converting service is to raise warnings when a number ofpresentation attributes detected in the first specification aredetermined to be non universal or non standard.
 25. The system of claim20, wherein the converting service is to independently maintain thesecond specification for the active content independent of subsequentmodifications made to the active content or the first specification. 26.The system of claim 20, wherein the converting service is to log actionsused to convert the first specification to the second specification. 27.The system of claim 20, wherein the rendering service is to maintainstable versions for particular signatures associated with a document ofthe active content, and wherein when one of the particular signatures isselected the rendering service is to generate a stable version of thedocument that existed when that selected signature was made.